PHP部门浮动价值问题 [英] PHP Division Float Value Issue

问题描述

当我尝试获得余数时，它给出了无效的值.我试图保留两个十进制值，然后得到

When I Try get remainder, It gives invalid value. I am trying to get remained of two decimal values and I get

3.4694469519536E-18

3.4694469519536E-18

我的价值观是

 $x=0.1; $y=0.005;

我尝试了以下操作:

echo $ed = fmod(0.1,0.005);  OutPut:3.4694469519536E-18
echo $ed = ((floatval(0.1)) % (floatval(0.005)));

但是得到

Warning: Division by zero

但现实"为0.1会在 20 次中除以0.005.即0.1/0.005 = 20

But Reality is 0.1 will be divide by 0.005 in 20 times. i.e. 0.1/0.005 = 20

当我使用10%1 = 0时，同一函数返回正确的值.

The same function returns correct value when I use 10%1 = 0.

如何获得确切的余数. (我在JQuery中没有遇到相同的问题:))

How can I get the exact remainder. ( I don't face the same issue in JQuery :) )

检查变通方法:​​ PHP部门浮点值替代方案

推荐答案

%运算符仅适用于整数，因此它将浮点数截断为整数并尝试执行0 % 0，结果除以零.

The % operator just works on integers, so it truncates your floats to integers and tries to do 0 % 0, which results in a division by zero.

您唯一可以使用的是fmod().您在这里面临的问题是典型的浮点不精确度(该值接近"零).我会考虑忽略小于10 ^ -15的值.在PHP中没有真正的替代方法.

The only thing you can use is fmod(). The issue you face here is the typical floating point imprecision (the value is "nearly" zero). I'd consider to just ignore values smaller then 10^-15. There's no real alternative to this in PHP.

您可以尝试做的是真正的划分，然后，一些不精确的运气消失了. (如round(0.1 / 0.005) === 0.1 / 0.005)

What you could try is doing the real division, then, with a bit of luck traces of the imprecision disappear. (like round(0.1 / 0.005) === 0.1 / 0.005)

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